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Content-Language: en-US From: =?UTF-8?Q?Martin_Li=c5=a1ka?= To: gcc-patches@gcc.gnu.org Cc: Jan Hubicka References: <596c4483-864c-1d03-955c-69906171f037@suse.cz> <8e839057-51b4-a036-c9f2-8049e41d5814@suse.cz> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-11.8 required=5.0 tests=BAYES_00, BODY_8BITS, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, NICE_REPLY_A, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 07 Apr 2022 14:00:32 -0000 PING^3 On 3/24/22 11:22, Martin Liška wrote: > PING^2 > > On 3/4/22 14:47, Martin Liška wrote: >> PING^1 >> >> On 1/26/22 12:11, Martin Liška wrote: >>> Hello. >>> >>> Right now, switch lowering does not update basic_block::count values >>> so that they are uninitiliazed. Moreover, I've updated probability scaling >>> when a more complex expansion happens. There are still some situations where >>> the profile is a bit imprecise, but the patch improves rapidly the current situation. >>> >>> Patch can bootstrap on x86_64-linux-gnu and survives regression tests. >>> >>> Ready to be installed? >>> Thanks, >>> Martin >>> >>>      PR tree-optimization/101301 >>>      PR tree-optimization/103680 >>> >>> gcc/ChangeLog: >>> >>>      * tree-switch-conversion.cc (bit_test_cluster::emit): >>>      Handle correctly remaining probability. >>>      (switch_decision_tree::try_switch_expansion): Fix BB's count >>>      where a cluster expansion happens. >>>      (switch_decision_tree::emit_cmp_and_jump_insns): Fill up also >>>      BB count. >>>      (switch_decision_tree::do_jump_if_equal): Likewise. >>>      (switch_decision_tree::emit_case_nodes): Handle special case >>>      for BT expansion which can also fallback to a default BB. >>>      * tree-switch-conversion.h (cluster::cluster): Add >>>      m_default_prob probability. >>> --- >>>   gcc/tree-switch-conversion.cc | 51 ++++++++++++++++++++++++----------- >>>   gcc/tree-switch-conversion.h  |  8 +++++- >>>   2 files changed, 43 insertions(+), 16 deletions(-) >>> >>> diff --git a/gcc/tree-switch-conversion.cc b/gcc/tree-switch-conversion.cc >>> index 670397c87e4..d6679e8dee3 100644 >>> --- a/gcc/tree-switch-conversion.cc >>> +++ b/gcc/tree-switch-conversion.cc >>> @@ -1538,10 +1538,12 @@ bit_test_cluster::emit (tree index_expr, tree index_type, >>>         test[k].target_bb = n->m_case_bb; >>>         test[k].label = n->m_case_label_expr; >>>         test[k].bits = 0; >>> +      test[k].prob = profile_probability::never (); >>>         count++; >>>       } >>> >>>         test[k].bits += n->get_range (n->get_low (), n->get_high ()); >>> +      test[k].prob += n->m_prob; >>> >>>         lo = tree_to_uhwi (int_const_binop (MINUS_EXPR, n->get_low (), minval)); >>>         if (n->get_high () == NULL_TREE) >>> @@ -1629,6 +1631,11 @@ bit_test_cluster::emit (tree index_expr, tree index_type, >>>                     /*simple=*/true, NULL_TREE, >>>                     /*before=*/true, GSI_SAME_STMT); >>> >>> +  profile_probability subtree_prob = m_subtree_prob; >>> +  profile_probability default_prob = m_default_prob; >>> +  if (!default_prob.initialized_p ()) >>> +    default_prob = m_subtree_prob.invert (); >>> + >>>     if (m_handles_entire_switch && entry_test_needed) >>>       { >>>         tree range = int_const_binop (MINUS_EXPR, maxval, minval); >>> @@ -1639,9 +1646,10 @@ bit_test_cluster::emit (tree index_expr, tree index_type, >>>                       /*simple=*/true, NULL_TREE, >>>                       /*before=*/true, GSI_SAME_STMT); >>>         tmp = fold_build2 (GT_EXPR, boolean_type_node, idx, range); >>> +      default_prob = default_prob.apply_scale (1, 2); >>>         basic_block new_bb >>>       = hoist_edge_and_branch_if_true (&gsi, tmp, default_bb, >>> -                     profile_probability::unlikely ()); >>> +                     default_prob); >>>         gsi = gsi_last_bb (new_bb); >>>       } >>> >>> @@ -1662,14 +1670,12 @@ bit_test_cluster::emit (tree index_expr, tree index_type, >>>     else >>>       csui = tmp; >>> >>> -  profile_probability prob = profile_probability::always (); >>> - >>>     /* for each unique set of cases: >>>          if (const & csui) goto target  */ >>>     for (k = 0; k < count; k++) >>>       { >>> -      prob = profile_probability::always ().apply_scale (test[k].bits, >>> -                             bt_range); >>> +      profile_probability prob = test[k].prob / (subtree_prob + default_prob); >>> +      subtree_prob -= test[k].prob; >>>         bt_range -= test[k].bits; >>>         tmp = wide_int_to_tree (word_type_node, test[k].mask); >>>         tmp = fold_build2 (BIT_AND_EXPR, word_type_node, csui, tmp); >>> @@ -1908,9 +1914,13 @@ switch_decision_tree::try_switch_expansion (vec &clusters) >>>         /* Emit cluster-specific switch handling.  */ >>>         for (unsigned i = 0; i < clusters.length (); i++) >>>       if (clusters[i]->get_type () != SIMPLE_CASE) >>> -      clusters[i]->emit (index_expr, index_type, >>> -                 gimple_switch_default_label (m_switch), >>> -                 m_default_bb, gimple_location (m_switch)); >>> +      { >>> +        edge e = single_pred_edge (clusters[i]->m_case_bb); >>> +        e->dest->count = e->src->count.apply_probability (e->probability); >>> +        clusters[i]->emit (index_expr, index_type, >>> +                   gimple_switch_default_label (m_switch), >>> +                   m_default_bb, gimple_location (m_switch)); >>> +      } >>>       } >>> >>>     fix_phi_operands_for_edges (); >>> @@ -2162,6 +2172,7 @@ switch_decision_tree::emit_cmp_and_jump_insns (basic_block bb, tree op0, >>>     edge false_edge = split_block (bb, cond); >>>     false_edge->flags = EDGE_FALSE_VALUE; >>>     false_edge->probability = prob.invert (); >>> +  false_edge->dest->count = bb->count.apply_probability (prob.invert ()); >>> >>>     edge true_edge = make_edge (bb, label_bb, EDGE_TRUE_VALUE); >>>     true_edge->probability = prob; >>> @@ -2192,6 +2203,7 @@ switch_decision_tree::do_jump_if_equal (basic_block bb, tree op0, tree op1, >>>     edge false_edge = split_block (bb, cond); >>>     false_edge->flags = EDGE_FALSE_VALUE; >>>     false_edge->probability = prob.invert (); >>> +  false_edge->dest->count = bb->count.apply_probability (prob.invert ()); >>> >>>     edge true_edge = make_edge (bb, label_bb, EDGE_TRUE_VALUE); >>>     true_edge->probability = prob; >>> @@ -2227,7 +2239,7 @@ switch_decision_tree::emit_case_nodes (basic_block bb, tree index, >>>                    node->m_c->m_case_bb, p, loc); >>>         /* Since this case is taken at this point, reduce its weight from >>>        subtree_weight.  */ >>> -      node->m_c->m_subtree_prob -= p; >>> +      node->m_c->m_subtree_prob -= node->m_c->m_prob; >>> >>>         if (node->m_left != NULL && node->m_right != NULL) >>>       { >>> @@ -2246,6 +2258,7 @@ switch_decision_tree::emit_case_nodes (basic_block bb, tree index, >>>              / (node->m_c->m_subtree_prob + default_prob)); >>>             bb = do_jump_if_equal (bb, index, node->m_right->m_c->get_low (), >>>                        node->m_right->m_c->m_case_bb, p, loc); >>> +          node->m_c->m_subtree_prob -= node->m_right->m_c->m_prob; >>> >>>             p = (node->m_left->m_c->m_prob >>>              / (node->m_c->m_subtree_prob + default_prob)); >>> @@ -2262,6 +2275,7 @@ switch_decision_tree::emit_case_nodes (basic_block bb, tree index, >>>             p = ((node->m_right->m_c->m_subtree_prob >>>               + default_prob.apply_scale (1, 2)) >>>              / (node->m_c->m_subtree_prob + default_prob)); >>> +          test_bb->count = bb->count.apply_probability (p); >>>             bb = emit_cmp_and_jump_insns (bb, index, node->m_c->get_high (), >>>                           GT_EXPR, test_bb, p, loc); >>>             default_prob = default_prob.apply_scale (1, 2); >>> @@ -2348,21 +2362,28 @@ switch_decision_tree::emit_case_nodes (basic_block bb, tree index, >>>        is the one to branch to.  */ >>>         if (node->has_child () || node->m_c->get_type () != SIMPLE_CASE) >>>       { >>> +      bool is_bt = node->m_c->get_type () == BIT_TEST; >>> +      int parts = is_bt ? 3 : 2; >>> + >>>         /* Branch to a label where we will handle it later.  */ >>>         basic_block test_bb = split_edge (single_succ_edge (bb)); >>>         redirect_edge_succ (single_pred_edge (test_bb), >>>                     single_succ_edge (bb)->dest); >>> >>> - >>> -       profile_probability right_prob = profile_probability::never (); >>> -       if (node->m_right) >>> -         right_prob = node->m_right->m_c->m_subtree_prob; >>> -      p = ((right_prob + default_prob.apply_scale (1, 2)) >>> +      profile_probability right_prob = profile_probability::never (); >>> +      if (node->m_right) >>> +        right_prob = node->m_right->m_c->m_subtree_prob; >>> +      p = ((right_prob + default_prob.apply_scale (1, parts)) >>>              / (node->m_c->m_subtree_prob + default_prob)); >>> +      test_bb->count = bb->count.apply_probability (p); >>> >>>         bb = emit_cmp_and_jump_insns (bb, index, node->m_c->get_high (), >>>                       GT_EXPR, test_bb, p, loc); >>> -      default_prob = default_prob.apply_scale (1, 2); >>> + >>> +      default_prob = default_prob.apply_scale (1, parts); >>> +      node->m_c->m_subtree_prob -= right_prob; >>> +      if (is_bt) >>> +        node->m_c->m_default_prob = default_prob; >>> >>>         /* Value belongs to this node or to the left-hand subtree.  */ >>>         p = node->m_c->m_prob / (node->m_c->m_subtree_prob + default_prob); >>> diff --git a/gcc/tree-switch-conversion.h b/gcc/tree-switch-conversion.h >>> index e969c051a05..5f3f99353ba 100644 >>> --- a/gcc/tree-switch-conversion.h >>> +++ b/gcc/tree-switch-conversion.h >>> @@ -102,6 +102,10 @@ public: >>>     /* Probability of reaching subtree rooted at this node.  */ >>>     profile_probability m_subtree_prob; >>> >>> +  /* Probability of default case when reaching the node. >>> +     It is used by bit-test right now.  */ >>> +  profile_probability m_default_prob; >>> + >>>   protected: >>>     /* Default constructor.  */ >>>     cluster () {} >>> @@ -110,7 +114,8 @@ protected: >>>   cluster::cluster (tree case_label_expr, basic_block case_bb, >>>             profile_probability prob, profile_probability subtree_prob): >>>     m_case_label_expr (case_label_expr), m_case_bb (case_bb), m_prob (prob), >>> -  m_subtree_prob (subtree_prob) >>> +  m_subtree_prob (subtree_prob), >>> +  m_default_prob (profile_probability::uninitialized ()) >>>   { >>>   } >>> >>> @@ -542,6 +547,7 @@ public: >>>     basic_block target_bb; >>>     tree label; >>>     int bits; >>> +  profile_probability prob; >>> >>>     /* Comparison function for qsort to order bit tests by decreasing >>>        probability of execution.  */ >> >